THE MUSOULAB SYSTEM 175
hurnerus. It is fused to BL variable extent with the teres major and dorso-epitrochlearis.
>pina5 o:i.ln C .-tti! o:'^... Iliac r.rij::.
Gorilla tSommer) .. Lower 5 dorsal spines Ribs S13 ) T; 3& in. beciiid
,, (Duvernoy) ,. ...... 2 ribs - the anierior
., (Bischoff) .. .. . .. 4 j -uperi or t=pirie
Chimpanzee (Sonntagj Dorsal spines 913 , Ribs 9II
,, (Champneysi ......., 1013 Highest point
,, (Hepburn) .. .. .. 3 costal ^lips " to uiac spine
,. (Gratiolet) .. .. ..5 ,,
Orang-Outan iFick) ., Lower 3 spine? .. Xo ecstal slip- Tc \vithin half
j """ < * - ^
aniuciicf ine iliac spine
Bornean Gibbon .. Lower 5 spines .. j Lower 5 r;"i;s iliddle third oi
The rhomboideus is usually undivided, but Champ-neys (318) described a divided sheet. Its origin extends in the Chimpanzee from the sixth cervical to the fourth dorsal spine; in the Gibbon the origin is much as in the Chimpanzee; in the Gorilla it extends from the spine of the axis to a point which varies from the third to the sixth dorsal spine; in the Orang its origin reaches up to the occiput. Gratiolet (330) described an occipital origin in a Chimpanzee. The muscle is inserted into the lower two-thirds to three-fourths of the vertebral border of the scapula, there being individual differences in the extent in each Ape.
The levator anguli scapulae exhibits great individual variation both in the extent of its origin and the degree to which the slips of origin fuse. It may be a single mass, as in most specimens, but Chimpanzees and Orangs have been seen in which the slips of origin remain separate to near the insertion into the upper part of